The Exchange Server Subscription Edition (SE) has emerged as a game-changer in the domain of on-premises email infrastructure. The erstwhile Exchange Server 2019 and 2016 versions used to leverage the traditional Cumulative Update (CU) model with a limited set of features. Capitalizing on these previous editions and the legacy servers, the SE version works on a subscription model, provides enhanced security, and features a modern architectural lifecycle.
Sensing its importance in enhancing the email system, organizations are now rapidly migrating to Exchange Server SE from Exchange 2016 and 2019. Specifically, after the end of Microsoft’s extended support to Exchange Server 2016 in October 2025, the migration has become a necessity for organizations. Eventually, the instant demand for successful migration through appropriate methods has become indispensable. To help your purpose, this blog discusses multiple ways to migrate from Exchange 2016 to Exchange Server SE.
Exchange Server Subscription Edition (SE)
Released on July 1, 2025, the Subscription Edition of MS Exchange Server is a Release to Manufacturing (RTM) build. This means it represents the first official base version of a subscription-based Exchange Platform, preventing its coexistence with Exchange Server 2013. Here are some of its plus points:
Equips the Exchange Server with a fresh set of features, services, and technologies
An advanced messaging platform offering email, tools, and scheduling for messaging apps and custom collaboration
Supports organizations and individuals in transforming their work habits from communication to collaboration
Mitigates the ownership cost whether you opt for cloud hosting of your mailboxes or choose to deploy on-premises Exchange SE
These advanced options, followed by the end of Microsoft support for Exchange Server 2016, prompt the organizations to migrate to Exchange Server SE
Methods for migration to Exchange SE
Usually, admins try two methods for migrations – Legacy upgrade and In-Place upgrade. While a legacy upgrade helps to move from Exchange Server 2016 to 2019 or SE, an in-place upgrade supports the migration of Exchange Server 2019 to SE. Here, our focus will be on migrating Exchange Server 2016 to Exchange Server SE. Therefore, we will discuss the legacy upgrade only.
What are the benefits of Legacy Upgrade?
This method involves adding a new server to the organization to migrate mailboxes and resources from the current server to Exchange Server SE. The completion of the migration process will follow the uninstallation of previous servers. Legacy upgrade serves multiple advantages:
Modernizes email infrastructure
Establishes an optimized and clean environment
The Subscription Edition servicing model vouches for a longer support lifecycle
Allows coexistence of both versions with minimal downtime
Removes deprecated legacy features that are no longer in use in Modern Exchange, such as Unified Messaging (UM),
Prerequisites for Migration from Exchange 2016 to Exchange Server SE
Mentioned below are some of the major prerequisites to migrating from Exchange 2016 to Exchange Server SE:
Ensure the latest cumulative updates (CU) for your existing Exchange Server
Have a supported and updated Active Directory Schema
Install the Exchange Server SE, with the host having Windows Server 2019 or a later version
Maintain a copy of all the specific or wildcard certificates
Keep the documentation about relaying and routing configurations, and connectors updated to the latest changes
Exchange Server Subscription Edition (SE) Installation
Installing Subscription Edition requires you to have a server with Windows Server 2019 or a later version. In addition, ensure the connection of Exchange Server 2019 and 2016 with the same domain. Both the server editions should fulfill the storage and computation requirements recommended by Microsoft and your chosen vendor. Once you complete the installation of SE, look for the following:
Proper creation of all the required databases
Installation of the requisite keys, activation, and certification
Correct configuration of all the involved domains
Accurate creation of Send and Receive connectors
All the services in working conditions, such as Outlook Anywhere, Autodiscover, etc.
How to carry out the mailbox migration to Exchange Server SE?
Since you have a coexisting Exchange Server 2016 and SE with all the correct configurations, your next task is to create a new test mailbox. Next, connect this test mailbox with MS Outlook to verify the email delivery and access. This is a necessary step before you start migrating the live Exchange Server data.
Use the PowerShell cmdlet New-MoveRequest to migrate mailboxes from Exchange Server 2016 to SE by using the below command:
New-MoveRequest -Identity "" -TargetDatabase "" -BatchName "" -Priority High
This will initiate user migration from the source to the target database. Here is the brief info on the parameters used:
BatchName: optional, used to easily track batches
Priority: Can be High, Normal, or Low based on the users’ criticality
Here are additional options to use with this command:
-ArchiveOnly $false: Include the archive mailbox
-SuspendWhenReadyToComplete: For coordination of moves and scheduled cutover. Can pause the mailbox migration between 95% to 99%.
Resume-MoveRequest -Identity djon@contoso.com: Resume after pause and finalize the move
To track the progress, use the Get-MoveRequestStatistics cmdlet as shown below:
Get-MoveRequestStatistics -Identity "" | Format-List
Here is the command to track the move request with the Suspend parameter,
Get-MoveRequest | Where-Object {$_.SuspendWhenReadyToComplete -eq $true}
If the move request succeeds, you can move multiple mailboxes together in a batch. For this, you should prepare the CSV file with the below comma-separated syntax:
Identity, TargetDatabase, BatchName, Priority
Next, run the migration batch by using the following command:
$importfile = Import-Csv -Path "" foreach ($mb in $importfile) {New-MoveRequest -Identity $mb.Identity -TargetDatabase $mbx.TargetDatabase -BatchName $mbx.BatchName -Priority $mbx.Priority -SuspendWhenReadyToComplete}
Start the migration by running the command below:
New-PublicFolderMigrationRequest -SourceDatabase "" -TargetMailbox "" -CSVData ([System.IO.File]::ReadAllBytes(""))
Complete the move with the help of Complete-MigrationBatch cmdlet.
To know the status of the migration command, use the following command:
Get-PublicFolderMigrationRequest | Get-PublicFolderMigrationRequestStatistics
How to migrate public folders to Exchange Server SE?
Just like you moved mailboxes to a new server, you can also move public folders with slightly different steps.
Create public folders in the new Exchange Server by using the following command:
New-Mailbox -PublicFolder -Name "" -Database ""
Make the public folder static through the following PowerShell command:
Get-PublicFolder -Recurse | Export-Csv .\
Get-PublicFolderStatistics -ResultSize Unlimited | Export-Csv .\
Next, create the mailbox mapping file through the following format:
Folderpath, TargetMailbox \Marketing, PublicFolder1\Sales, PublicFolder2
Steps to follow post migration to Exchange Server SE
After moving the mailboxes and public folders, abide by the following practices:
Monitor the flow and delivery of email
The perimeter firewalls should route to the new server
Ensure an updated document and proper backups
Ensure a properly decommissioned Exchange Server
Challenges you may face during the migration
When migrating from Exchange 2016 to Exchange Server SE, you may come across several issues:
Pending mailbox move request
Mailboxes in suspend state
Large mailboxes or archive issues
Exchange Server misconfiguration
Public folder quotas
No support for cross-domain and cross-forest migrations
Wrong commands written by the user
These issues can make the migration a daunting task, compelling the administrators to use an Exchange migrator tool as an alternative.
Why use an Exchange migrator application?
An automated Exchange migrator tool can migrate mailboxes across Exchange Servers, including the Subscription Edition, with ease. Alongside, you can also use it to carry out the same and cross-domain migration without requiring the execution of complicated PowerShell scripts. Here are more advantages of using this tool from a reputable organization:
Concurrent mailbox migrations
Automated Mailbox Matching
Support for Cutover, staged, and hybrid migration
Exchange to Exchange and Office Migration
Office 365 to Office 365 and Exchange Migration
Selective Mailbox Folder Migration
Stellar Migrator for Exchange is a feasible migration tool to provide all these and many more benefits. You can also use it to perform an Exchange Server 2016 to Exchange Server SE migration.
Conclusion
The introduction of Exchange Server Subscription Edition in the realm of on-premises email infrastructure has given users a welcome alternative. Users now prefer to migrate their mailboxes from Exchange Server 2016 and 2019 to SE owing to the multiple advanced features it accompanies. Specifically, for the users of Exchange Server 2016, migration has become an unavoidable need due to the end of support for Microsoft.
Usually, admins leverage the in-place upgrade for Exchange Server 2019 migration and the legacy upgrade method for Exchange Server 2019 migration to Exchange Server SE. To continue with the legacy upgrade, take care of the major prerequisites, including the installation of the Subscription Edition. Following it, you can carry out the mailbox migration and public folder migration by using various PowerShell commands.
However, moving the mailboxes or public folders using these lengthy and complicated commands could cause several human or automated issues. In order to eliminate the possibility of such challenges, admins prefer using several Exchange migrator tool. Of the many applications available online for migrating from Exchange 2016 to Exchange Server SE, Stellar Migrator for Exchange can be a feasible option.
